The Third Conditional if + past perfect, + would have + past participle would have + past participle + if + past perfect We use the third conditional when talking about events that have already, happened. This is used when it is impossible for the condition to be fulfilled as the time for it to happen has already passed. • If I had started earlier, I would have finished the work by now. Or: . I would have finished the work by now if I had started earlier. Exercises: Be sure to use the contracted form of the verb i.e. hadn't' rather than 'had not'. 1. If I (know) you were coming, I (bake) a cake. 2. If I (accept) that promotion, I (work) in Milan. 3. If it (not/rain), I (got) wet. 4. If she (see) the ball, it (not/hit) her on the head.